Method for the conditioning of air, and air-conditioning system

ABSTRACT

In order to provide a method for the conditioning of air which is implementable in a reliable and energy-efficient manner, it is proposed that the method comprise the following:
         determining the actual values of at least two parameters of an inlet air stream of a conditioning system in which the air is to be conditioned;   selecting an operating state of the conditioning system on the basis of a model by means of which a plurality of possible actual values of the at least two parameters is linked to operating states of the conditioning system;   setting the conditioning system into the selected operating state so that an output air stream of the conditioning system is produced in which the actual values of the at least two parameters lie within preset target value ranges.

The present invention relates to a method for the conditioning of air.

Such a method is known from EP 1 081 442 A1 for example. This knownmethod is a regulated method wherein a conditioning system is regulatedby means of regulated actuators. Thereby, at least one of the regulatorinput variables that are needed for the regulation of the conditioningsystem is a mixed regulator input variable which is formed by linking adeviation from the target temperature value with a deviation from thetarget humidity value.

The object of the present invention is to provide a method for theconditioning of air which is implementable in a reliable andenergy-efficient manner.

In accordance with the invention, this object is achieved in that themethod for the conditioning of air comprises the following:

-   -   determining the actual values of at least two parameters of an        inlet air stream of a conditioning system in which the air is to        be conditioned;    -   selecting an operating state of the conditioning system on the        basis of a model by means of which a plurality of possible        actual values of the at least two parameters is linked to        operating states of the conditioning system;    -   setting the conditioning system into the selected operating        state so that an output air stream of the conditioning system is        produced in which the actual values of the at least two        parameters lie within preset target value ranges.

Due to the fact that, in accordance with the invention, an operatingstate is selected on the basis of a model, a desired output air streamof the conditioning system can preferably be produced rapidly, reliablyand/or in energy-efficient manner.

In this description and the accompanying Claims, it is to be understoodin particular that a target value range is a range or a span of valueswithin which a desired parameter may move in order to ensure the desiredproperties of the air stream.

In particular, the model is a static and/or a dynamic model.

In one embodiment of the invention, provision is made for the operatingstate of the conditioning system to be selected on the basis of aparameter map by means of which a plurality of possible actual values ofthe at least two parameters is linked with the operating states of theconditioning system.

Furthermore, provision may be made for the operating state of theconditioning system to be selected on the basis of a correlationfunction by means of which a plurality of possible actual values of theat least two parameters is linked with the operating states of theconditioning system.

In this description and the accompanying Claims, a correlation functionis preferably to be understand as any equation and any set of equationsand in particular model equations and sets of model equations by meansof which a connection between at least one input quantity and at leastone output quantity is established.

The parameter map and/or the correlation function are preferably basedon the model upon the basis of which the operating state of theconditioning system is selected.

In particular, provision may be made for the parameter map and/or thecorrelation function to be or to have been established or produced byusing or upon the basis of a model.

In particular, the model is a simulation model and especially asimulation model of the conditioning system or a work-piece processingsystem which incorporates the conditioning system.

By means of the model and preferably using the actual values of the atleast two parameters of the inlet air stream and with knowledge of theoperating state of the conditioning system, the actual values of the atleast two parameters of the output air stream of the conditioning systemcan be determined and especially computed and/or predicted.

In particular in the inverse situation, it is additionally preferablypossible by means of the model and with knowledge of the preset targetvalue ranges of the at least two parameters of the output air stream ofthe conditioning system and by use of the determined actual values ofthe at least two parameters of the inlet air stream to deduce a desiredoperating state of the conditioning system.

In particular, a parameter map can be produced by means of the modelfrom which, by using the determined actual values of the at least twoparameters of the inlet air stream, an optimized and/or particularlyenergy-efficient operating state of the conditioning system isderivable.

In particular, provision may be made for control signals for theconditioning system by means of which the conditioning system issettable into the desired operating state to be providable by means ofthe parameter map.

Alternatively or in addition to a parameter map, provision may be madefor a correlation function by means of which a plurality of possibleactual values of the at least two parameters is linked with theoperating states of the conditioning system.

Particularly when the conditioning system is in operation, an efficientoperating state of the conditioning system can be computed by means ofthe correlation function on the basis of the model using the determinedactual values of the at least two parameters of the inlet air stream inorder to ensure adherence to the target value ranges of the parametersof the output air stream.

It can be expedient for one parameter to be the air temperature.

A (further) parameter is preferably the air humidity (moisture content).

It can be particularly advantageous if the at least two parameters forma pair of parameters consisting of the air temperature and the airhumidity (moisture content).

It can be expedient for the inlet air stream to be heated up and/orcooled.

As an alternative or in addition thereto, provision may be made for theinlet air stream to be humidified and/or dehumidified.

In one embodiment of the invention, provision is made for a plurality ofpossible actual value combinations and in particular pairs of actualvalues of the at least two parameters to be linked with a respectiveoperating state of the conditioning system by means of the model.

In particular, provision may be made for an operating state of theconditioning system to be associated with the plurality of possiblepairs of actual values, especially the air humidity and the airtemperature together, by means of the model.

In particular, a plurality of possible actual values of the at least twoparameters is linked with pre-defined operating states of theconditioning system by means of the model, the parameter map and/or thecorrelation function.

The operating states of the conditioning system preferably each comprisean operating state of a humidification device, an operating state of adehumidifying device, an operating state of a heating device and/or anoperating state of a cooling device.

In particular, provision may be made for the pre-defined operatingstates of the conditioning system to each comprise a pre-definedoperating state of a humidification device, a pre-defined operatingstate of a dehumidifying device, a pre-defined operating state of aheating device and/or a pre-defined operating state of a cooling device.

A pre-defined operating state is, in particular, an operating statewhich is determined and in particular computed and/or simulated on thebasis of the model before carrying out the method for the conditioningof air.

The operating states of the conditioning system selectable on the basisof the model are preferably pre-defined operating states of theconditioning system.

In particular, controlled operation of the conditioning system isimplementable by selecting an operating state of the conditioning systemon the basis of the model and setting the conditioning system into theselected operating state. The controlled operation of the conditioningsystem is especially independent of actual values of the at least twoparameters of the output air stream of the conditioning system.

Provision may be made for the conditioning system to be set into areadjusting operating state in which a deviation of the actual values ofthe at least two parameters of the output air stream from the presettarget values is determined and in which, for the purposes of furtherapproximation to or equalisation of the actual values with the targetvalues, readjustment of the conditioning system is effected.

A readjustment or a readjusting operating state of the conditioningsystem is to be understood in particular as being a supplementaryregulation of the conditioning system on the basis of the controlledoperating state.

In particular, provision may be made for the conditioning system to beset into the readjusting operating state after having been set into theselected operating state wherein a deviation of the actual values of theat least two parameters of the output air stream from the preset targetvalues is determined and wherein, for the purposes of closerapproximation to or equalisation of the actual values with the targetvalues, readjustment of the conditioning system is effected.

In particular hereby, provision may be made for the humidificationdevice, the dehumidifying device, the heating device and/or the coolingdevice to be set into a readjusting operating state.

In one embodiment of the invention, provision may be made for adetermination to be made by means of a monitoring device as to whether adeviation of the actual values of the at least two parameters of theoutput air stream from the preset target values exceeds a preset maximumdeviation. In order in particular to enable the proper functioning ofthe conditioning system to be monitored, the magnitude of the deviationsof the actual values of the at least two parameters of the output airstream from the preset target values can preferably be determined.

A malfunction of the conditioning system can preferably be establishedor determined by means of the monitoring device.

The air that has been conditioned by means of the method according tothe invention and in particular the output air stream from theconditioning system can be used in particular in a work-piece processingsystem.

Consequently, the present invention also relates to a method ofsupplying air to a work-piece processing system.

The method of supplying air to a work-piece processing system inaccordance with the invention preferably comprises particular ones or aplurality of the features and/or advantages described in connection withthe method for the conditioning of air in accordance with the invention.

It can be expedient for the output air stream of the conditioning systemto be supplied to a processing area of the work-piece processing systemin the form of a processing air stream.

Hereby, the plurality of possible actual values of the at least twoparameters of the inlet air stream of the conditioning system ispreferably linked with the operating states of the conditioning systemby means of the model so that the derivable actual values of the atleast two parameters of the processing air stream lie within presettarget value ranges.

Hereby, the output air stream of the conditioning system can be just apart of a processing air stream or it may form the entire processing airstream for example.

In particular, if the output air stream of the conditioning system is apart of the processing air stream, then the remaining part of theprocessing air stream can be a circulating air stream that is fed intothe work-piece processing system.

If the output air stream of the conditioning system forms the entireprocessing air stream, then a supply of pure air is preferably providedto the work-piece processing system.

Particularly in the case where the output air stream of the conditioningsystem forms a part of the processing air stream, provision may be madefor the effect of the circulating air stream being fed through an aircirculation system on the actual values of the at least two parametersof the processing air stream to be taken into account in the model forthe selection of the operating state of the conditioning system.

The model is preferably a model which is specific to the system.

Preferably, the dimensions of the work-piece processing system and inparticular the processing area of the work-piece processing system aretaken into account in the model.

Furthermore, provision may be made for the type, the extent and/or theduration of the work-piece processing operation that is being carriedout by means of the work-piece processing system to be taken intoaccount in the model.

The inlet air stream of the conditioning system can, in particular, be astream of fresh air or a circulating air stream or a mixture of a streamof fresh air and a circulating air stream.

The method in accordance with the invention is particularly suitable foroperating a conditioning system for the conditioning of air.

Consequently, the present invention also relates to a conditioningsystem for the conditioning of air.

In regard to this aspect, the object of the invention is to provide aconditioning system by means of which air is conditionable in a reliableand energy-efficient manner.

In accordance with the invention, this object is achieved by aconditioning system for the conditioning of air which comprises acontrol device and a measuring device for determining the actual valuesof at least two parameters of an inlet air stream of the conditioningsystem that is to be conditioned,

wherein an operating state of the conditioning system is selectable bymeans of the control device on the basis of a model by means of which aplurality of possible actual values of the at least two parameters islinked with operating states of the conditioning system, and

wherein the conditioning system is settable into the selected operatingstate by means of the control device so that an output air stream of theconditioning system is producible in which the actual values of the atleast two parameters lie within preset target value ranges.

The conditioning system in accordance with the invention preferablyincorporates particular ones or a plurality of the features and/oradvantages described above in connection with the methods in accordancewith the invention.

The conditioning system preferably comprises a control device forcontrolling the conditioning system and in particular the implementationof the method in accordance with the invention.

It can be expedient if the control device comprises a memory device inwhich a parameter map and/or a correlation function is stored, wherein aplurality of possible actual values of the at least two parameters islinked with the operating states of the conditioning system by means ofthe parameter map and/or by means of the correlation function.

The conditioning system preferably comprises a humidification device, adehumidifying device, a heating device and/or a cooling device.

In particular the cooling device may simultaneously be a dehumidifyingdevice.

Furthermore, provision may be made for the conditioning system tocomprise at least one filter device and/or at least one heat exchanger.

Preferably, heat is transferable from an exhaust air stream leaving awork-piece processing system to the inlet air stream of the conditioningsystem by means of the heat exchanger.

In one embodiment of the invention, provision is made for theconditioning system to comprise a regulating device by means of whichthe conditioning system is settable into a readjusting operating state.

In the readjusting operating state, a deviation of the actual values ofthe at least two parameters of the output air stream from the presettarget values is preferably determinable.

Furthermore, readjustment of the conditioning system for the purposes ofcloser approximation to or equalisation of the actual values with thepreset target values is preferably implementable in the readjustingoperating state.

Expediently, the conditioning system comprises a monitoring device bymeans of which it is determinable as to whether a deviation of theactual values of the at least two parameters of the output air streamfrom the preset target values exceeds a preset maximum deviation.

The conditioning system in accordance with the invention is suitable inparticular for use as a component or in combination with a work-pieceprocessing system.

Consequently, the present invention also relates to a work-pieceprocessing system which incorporates a conditioning system in accordancewith the invention.

Hereby, the work-piece processing system in accordance with theinvention preferably comprises particular ones or a plurality of thefeatures and/or advantages described above in connection with themethods in accordance with the invention and/or the conditioning systemin accordance with the invention.

The output air stream of the conditioning system is preferably feedableto a processing area of the work-piece processing system as a processingair stream.

Hereby, the plurality of possible actual values of the at least twoparameters of the inlet air stream of the conditioning system is linkedwith the operating states of the conditioning system by means of themodel in such a manner that the derivable actual values of the at leasttwo parameters of the processing air stream lie within preset targetvalue ranges.

The conditioning system can be in the form of an air supply systemand/or an air-recirculation system.

To this end, in addition to the humidification device, the dehumidifyingdevice, the heating device and/or the cooling device, the conditioningsystem preferably comprises a housing, at least one fan (blower), atleast one filter device (filter stage), a flow distributor, at least onesound proofing device (muffler) and/or at least one heat conveyer (heatexchanger), in particular, at least one thermal wheel.

Conditioning of air is to be understood in this description and theaccompanying Claims in particular as being the processing and/or thetreatment of air.

The work-piece processing system is particularly a surface processingsystem, a machining system, a coating system, a painting system, adrying system and/or a cleaning system.

The work-pieces are vehicles, vehicle parts, vehicle bodies, vehicleattachments, furniture and/or medical instruments for example.

Furthermore, the methods in accordance with the invention and/or thesystems in accordance with the invention may incorporate particular onesor a plurality of the features and/or advantages described below:

The conditioning of the air is preferably effected for the purposes ofprocess-security and quality assurance of manufacturing processesespecially in the trade and industry fields.

A plurality of process steps are preferably implementable by means ofthe work-piece processing system and/or in the work-piece processingsystem especially the cleaning and/or degreasing of work-pieces,formation of a conversion layer on the work-pieces (e.g. phosphating),application of lacquer using a dipping process, application of lacquerusing a sputtering or spraying process, baking or hardening the lacquerfilm, checking the work-pieces and/or re-machining the work-pieces.

In particular when painting work-pieces, the following target value andtarget value ranges of the relative humidity and the temperature of theprocessing air stream are preferably used:

When using solvent-based lacquers, the relative humidity preferablyamounts to at least approximately 40% and/or at most to approximately84% and the temperature preferably amounts to at least approximately 20°C. and/or at most approximately 30° C.

When using water-based lacquers, the relative humidity preferablyamounts to at least approximately 60% and/or at most approximately 70%and the temperature preferably amounts to at least approximately 20° C.and/or at most approximately 26° C.

When using a single layer water finish coating, the relative humiditypreferably amounts to at least approximately 55% and/or at mostapproximately 75% and the temperature preferably amounts to at leastapproximately 20° C. and/or at most approximately 26° C.

When using a powder coating particularly powder filler, the relativehumidity preferably amounts to at least approximately 40% and/or at mostapproximately 50% and the temperature preferably amounts to at leastapproximately 20° C. and/or at most approximately 24° C.

Furthermore, when using a powder coating and especially a powderedclear-lacquer, provision may be made for the relative humidity to amountto at least approximately 40% and/or at most approximately 50% and forthe temperature to preferably amount to at least approximately 18° C.and/or at most approximately 22° C.

In individual cases however, such as for reasons of quality for example,provision may also be made for other types of climatic conditions(target values and target value ranges) to be used in dependence on thelacquer system and on the desired colour spectrum.

Provision may be made for the demands on the local air conditioning(conditioning of the processing air stream) in a processing area duringthe application of water-based lacquers in comparison with the demandson the local air conditioning during the application of solvent-basedlacquers to differ and in particular, to be narrower or higher. This,for example, can lie on the water dilutibility and on the specialdemands being made in regard to quality and appearance such as thereproducible nature and/or uniformity of the effect created in the caseof metallic paints or special effect paints for example.

The fresh air supply and the exhaust air requirements of a work-pieceprocessing device in the form of a vehicle paint shop for example forpainting 30 car bodies per hour can amount to up to approximately 1.4million cubic meters per hour for example. The fresh air supply and theexhaust air requirements can preferably be reduced by at least half byreducing the layers of lacquer, the extent of the lacquer and by partialre-circulation of the air within the processing area (spray-booth).

It can be expedient for a large part, at least approximately 50% forexample and in particular approximately 80% for example, of the air forconditioning the local region (the processing air stream) to bere-circulated. In particular in the case of a paint shop using a drydeposition process or an electrical deposition process, the air beingfed into the air circulation system can be heated up by the frictionalheat of the fan (blower) for example. This can preferably be compensatedfor by means of a cooling device in the conditioning system especiallyin an air re-circulating system.

In particular for the purposes of removing pollutants, a portion of thecirculating air, approximately 20% for example, is preferably removedand supplied to an exhaust air purification system for example. Theremoved portion of the circulating air is preferably replaced by meansof an air supply system, especially a smaller one.

In dependence upon the manufacturing location and the lacquer systembeing utilised, different demands may be made on the dimensioning andregulation of an air supply system and/or an air re-circulating system.

In the case of very cold locations for example, it is possible todispense with a cooling device because even in the summer months, hightemperatures which would make it necessary for the supplied air to becooled are not expected.

In the case of a hot humid location in which large variations intemperature and/or humidity fluctuations occur over the whole year forexample, a desired conditioning of the air can preferably be effectedmore easily by means of a cooling device.

However, independently of the location of the conditioning system and/orthe work-piece processing system, weather reversals due to the onset ofthunderstorms with a resultant rapid rise of the relative air humidityfor example can impose great demands on the outlay required for theregulation of the conditioning system. This outlay for the regulationprocess can preferably be simplified and the conditioning systemoperated more reliably and more energy-efficiently by the purposefulselection of an operating state of the conditioning system on the basisof a model.

A target value range or the target value ranges of the at least twoparameters of the processing air stream is also referred to as a spraybooth air conditioning window or as a “Drying Line” for example.

Provision may be made for the target value ranges to comprise individualpreferred working points for the winter and the summer for example.

The working points are preferably fixed during the design stage of theconditioning system and/or the work-piece processing system.

Preferably, a process of coordinating the conditioning devices of theconditioning system, especially a humidification device, a dehumidifyingdevice, a heating device and/or a cooling device is effected by means ofa global model which takes into account the ambient temperature and theambient humidity of the conditioning system. The regulation process canpreferably be pre-programmed by system parameters.

It can be expedient for the regulation process to be divided into aforward path (pilot control) and a return path (regulation). The pilotcontrol process is preferably effected by selecting the operating stateon the basis of the model. The regulation process is preferably there-adjustment process.

In particular, provision may be made for the pilot control process tocompute an energy-optimal correcting variable combination for theconditioning devices of the conditioning system and an optimal targetvalue within a preset target value range based in particular on themodel by the solution of an optimisation problem.

Preferably, an optimal solution is computed from the temperature andhumidity of the inlet air stream.

It can be expedient if the pilot control signal (a control signal from acontrol device) by means of which the conditioning system is settableinto the selected operating state is supplemented by a regulating signal(re-adjustment; a control signal from a regulating device). Theregulating signal is preferably computed using the actual values of thetemperature and humidity of the out-flowing air (the output air stream).

A two-degrees of freedom structure can preferably be realized by meansof the pilot control process and the regulation process.

In particular in the case where the regulating structure comprises amodel of the conditioning system, the controlling strategy for theindividual conditioning devices (modules) can preferably be designed insuch a way that an energy-optimal operation is immanently impressed forexample.

It can be particularly advantageous if the regulation concept forindustrial conditioning systems is based on a global model-set for anenergy-optimal regulation process.

The adjusting signals (the control signals and/or regulating signals forthe setting of the operating states) for the individual conditioningdevices are preferably coordinated centrally.

Preferably, changes in strategy can be taken into account in the eventof sudden weather reversals for example.

Furthermore, correcting variable combinations as well as target valuescan preferably be computed in an energy-optimal manner.

The algorithms for the computation strategy are preferably adapted tothe process control hardware and/or process control software that aretypical of air supply systems and/or air recirculation systems.

In particular hereby, the complex optimisation problem can be reduced toa numerically highly-efficiently solvable linear optimisation problem.The solution of the complex problem is preferably sufficiently preciselyapproximated by the successive solution of the reduced problem.

Provision may be made for the coordinating regulation process to bepre-programmed by physically interpretable system parameters.

Preferably, substantial cost savings and/or savings of time can beachieved compared with decentralized solutions particularly in regard tothe large time constants in air supply systems and/or air re-circulationsystems.

Preferably, the danger of oscillation of the conditioning devices andthe development of limit cycles can be reduced or in particular,completely prevented.

Preferably, thermodynamic reciprocal effects such as the coupling oftemperature and relative humidity for example are taken into account inthe model. Preferably thereby, the behaviour of the control systemand/or the regulating action can be optimised.

It can be expedient if the controlling behaviour and/or the regulatingaction of a system especially that of a conditioning system and/or awork-piece processing system can be simulated in advance during thedesign stage. In particular, an automatic model-based parameterpre-setting process can be effected. Preferably thereby, anydeficiencies in the system in regard to the dynamic control, regulatingand error-response behaviour can be recognized in advance in an earlyproject phase.

Preferably furthermore, access to a differentiated fault-tracing processcan be provided by the use of a model. Actual values of parameters(system parameters) deviating from the expected values can lead to adeviation from a static behaviour in accordance with the model. Achanged pattern of behaviour of the regulation process can resulttherefrom and this can be used for diagnostic purposes.

The preset target value range is preferably the number of working pointson a connecting line in the air temperature-air humidity diagram (orenthalpy-humidity diagram) between a summer working point and a winterworking point.

Preferably, the ambient temperature and the ambient humidity as well asthe connecting line between the summer working point and the winterworking point in the air temperature-air humidity diagram are used forthe process of computing optimal correcting variables and an optimaltarget value.

The connecting line can also be referred to as a Drying Line.

The pilot control process preferably enables coordination of theindividual conditioning devices based on a model especially a physicalone.

For the purposes of optimising the actual values of the at least twoparameters of the output air stream that are attainable in the selectedoperating state of the conditioning system, a re-adjustment process ispreferably effected such as by means of an output feedback arrangementfor example.

For the realization of the regulation process, provision may preferablybe made for known methods of solution such as a decentralized regulatorusing linear PI regulators for example.

Preferably, the target values of the at least two parameters of theoutput air stream are computed in order to ensure consistent regulatingsignals in relation to the control signals.

The correcting variable component of the regulation process ispreferably calculated from the difference between the actual values ofthe at least two parameters of the output air stream and theappertaining target values.

Alternatively or in addition to a decentralized regulation process,provision may also be made for a model-based, linear MIMO regulationprocess.

The pilot control process and the regulation process together preferablyform a coordinating temperature and humidity regulation process.

The conditioning system may preferably be monitored by monitoring theagreement between the system behaviour and a model behaviour, especiallya simulated model. A control signal of a control device of theconditioning system then needs to be corrected by means of a regulatingdevice to a lesser extent the more the model behaviour agrees with thesystem performance.

An incorrectly functioning operating state can preferably be detected bya changed regulating component. In particular, abruptly occurring faultssuch as a mal-positioned valve for example and/or long-term effects suchas wear and tear for example can then be recognized.

In particular, abruptly occurring faults can be directly detected andare diagnosed by warning signals.

Long-term effects can preferably be determined by statistical evaluationof the regulating components.

Further preferred features and/or advantages of the invention form thesubject matter of the following description and the graphicalillustration of exemplary embodiments.

In the drawings:

FIG. 1 shows a schematic sectional view through a work-piece processingsystem which comprises a conditioning device for the conditioning ofair;

FIG. 2 a schematic sectional view of a further conditioning system;

FIG. 3 a schematic illustration for illustrating the functioning of aconditioning system;

FIG. 4 a schematic illustration for illustrating the control andregulation of a conditioning system;

FIG. 5 a diagram for illustrating the mode of operation of aconditioning system;

FIG. 6 a schematic diagram corresponding to FIG. 5 for illustratingdifferent operational areas of a conditioning system;

FIG. 7 a schematic illustration for illustrating the manner ofcontrolling a conditioning system; and

FIG. 8 a further schematic illustration for illustrating the manner ofcontrolling a conditioning system.

The same or functionally equivalent elements are provided with the samereference symbols in all of the Figures.

A work-piece processing system bearing the general reference 100 whichis illustrated in FIG. 1 is in the form of a painting facility 102 forpainting work-pieces 103 and in particular vehicle bodies for example.

For this purpose, the work-piece processing system 100 comprises aprocessing area 104, particularly one in the form of a paint booth 106,and an air feed device 108 by means of which an air stream is caused topass through the processing area 104.

This air stream is referred to as a processing air stream 109 in thefollowing.

The work-piece processing system 100 comprises a filtering unit 110 bymeans of which the processing air stream 109 being fed through theprocessing area 104 is cleanable.

In particular, provision may be made for paint overspray which waspicked up by the processing air stream 109 in the processing area 104 tobe separable from the processing air stream 109 by means of thefiltering unit 110.

The air feed device 108 comprises a conditioning system 114 in the formof an air supply system 112 for example.

Ambient air and in particular fresh air can be sucked in as an inlet airstream 152, conditioned and then supplied e.g. by way of a plenum 116 ofthe work-piece processing system 100 to the processing area 104 as aprocessing air stream 109 by means of the conditioning system 114.

The conditioning system 114 comprises an air supply duct 118, a blower120 for propelling the air stream as well as a plurality of conditioningdevices 122.

For example, the conditioning system 114 comprises a conditioning device122 in the form of a heating device 124, a conditioning device 122 inthe form of a cooling device 126, a conditioning device 122 in the formof a humidification device 128 and/or a conditioning device 122 in theform of a dehumidifying device 130.

The air stream being fed through the conditioning system 114 can thus beheated up, cooled, humidified and/or dehumidified by means of theconditioning device 122.

Furthermore, the conditioning system 114 comprises two filter devices132.

Hereby with respect to a direction of flow 134 of the air stream, afilter device 132 in the form of a pre-filter 136 is arranged upstreamof the conditioning devices 122, whilst a filter device 132 in the formof a post-filter 138 is arranged downstream of the conditioning devices122.

In particular, the conditioning devices 122, the filter devices 132 andthe blower 120 are arranged in a housing 150 of the conditioning system114.

An exhaust air duct 140 of the air feed device 108 serves for removingthe processing air stream 109 that has been cleaned by means of thefiltering unit 110.

The air supply duct 118 and the exhaust air duct 140 are preferablythermally coupled to one another by means of a heat exchanger 142.

The heat exchanger 142 is in the form of a thermal wheel 144 for exampleand serves, in particular, for conveying the heat of the air streambeing fed through the exhaust air duct 140 (the cleaned processing airstream 109) to the air stream being fed through the air supply duct 118(the inlet air stream 152).

Finally, the conditioning system 114 also comprises a measuring device146 by means of which the actual values of at least two parameters ofthe inlet air stream 152 of the conditioning system 114 being suppliedthrough the air supply duct 118 are determinable.

Optimal control or regulation of the conditioning system 114 and thus ofthe entire work-piece processing system 100 can be effected on the basisof the actual values that have been determined.

The work-piece processing system 100 illustrated in FIG. 1 functions asfollows:

The actual values of at least two parameters of the inlet air stream 152of the conditioning system 114 are determined by means of the measuringdevice 146. In particular, the air temperature and the air humidity andin particular, the relative humidity are determined.

On the basis of the actual values of the at least two parameters, theconditioning system 114 is set into a certain operating state in orderto deliberately condition the inlet air stream 152 in such a manner thatit will have a preset desired air temperature and a preset desired airhumidity after it has passed through the conditioning system 114 andthus as it is leaving the system in the form of the output air stream154 of the conditioning system 114.

The output air stream 154 of the conditioning system 114 is supplied tothe processing area 104 as a processing air stream 109.

Due to the fact that the processing air stream 109 exhibits a preset airtemperature and a preset air humidity, optimal conditions for theprocessing of the work-pieces 103 and in particular for painting thework-pieces 103 prevails in the processing area 104.

After flowing through the processing area 104, the processing air stream109 is cleaned by means of the filtering unit 110 and then expelledthrough the exhaust air duct 140.

The heat contained in the cleansed processing air stream 109 is at leastpartly transferred by means of the heat exchanger 142 to the inlet airstream 152 that is being fed through the air supply duct 118 and is thuspreferably not expelled unused into the environment of the work-pieceprocessing system 100.

An alternative embodiment of a conditioning system 114 which isillustrated in FIG. 2 basically differs from the embodiment illustratedin FIG. 1 in that the conditioning system 114 comprises two heatingdevices 124 as well as a sound proofing device 148.

In the case of the conditioning system 114 in accordance with FIG. 2,there is provided a heating device 124 which is in the form of a burner147 for example.

In relation to the direction of flow 134, the filter device 132 in theform of a pre-filter 136 is arranged downstream of this heating device124.

Following this filter device 132 in the direction of flow 134, there isthe cooling device 126, a heating device 124 in the form of a hot waterregister, the humidification device 128, the filter device 132 in theform of a post-filter 138 and the blower 120.

The sound proofing device 148 is arranged between the filter device 132in the form of a post-filter 138 and the blower 120.

In particular, the sound proofing device 148 is arranged to the side ona housing 150 of the conditioning system 114.

An inlet air stream 152 being supplied to the conditioning system 114can thus firstly be heated up, then cleaned and subsequently cooled,heated up again, humidified and lastly cleaned again by means of theconditioning system 114 illustrated in FIG. 2.

In all other respects, the alternative embodiment of the conditioningsystem 114 illustrated in FIG. 2 corresponds in regard to theconstruction and functioning thereof with the conditioning system 114 ofthe work-piece processing system 100 from FIG. 1, so that to this extentreference should be made to the previous description thereof.

The process of controlling and/or regulating the conditioning system 114are explained exemplarily hereinafter on the basis of a conditioningsystem 114 in which a cooling device 126, a heating device 124 and ahumidification device 128 are provided in serial succession.

As can be perceived from FIG. 3 in particular, an inlet air stream 152can be conditioned by means of the conditioning system 114. Theconditioned air stream leaves the conditioning system 114 as an outputair stream 154.

The cooling device 126 is in the form of a cooling register for example.

The heating device 124 is in the form of a heating register for example.

A variable flow of cooling water is preferably supplied to (notillustrated) register pipes of the cooling device 126 for cooling theair stream being fed through the conditioning system 114.

A variable flow of hot water is preferably supplied to (not illustrated)register pipes of the heating device 124 for heating the air streambeing fed through the conditioning system 114.

In particular, the streams of water are preferably controllable and/orregulable by (not illustrated) valves.

The humidification device 128 preferably comprises a controllable and/orregulable humidifier pump 156.

A variable, especially speed-regulated flow of water can be injectedinto the air stream being fed through the conditioning system 114 bymeans of the humidifier pump 156.

The flow rate of the air stream being fed through the conditioningsystem 114 is preferably kept constant by means of a blower 120 (seeFIGS. 1 and 2).

As can be perceived in particular from FIG. 3, each conditioning device122 can preferably be controlled by a separate control signal 158.

In principle therefore, the conditioning devices 122 can be controlledindividually and operated substantially independently of each other.

However, as can be perceived from FIG. 4 in particular, the conditioningsystem 114 preferably has a master control device 160 for controllingthe conditioning system 114.

The control device 160 is connected to a measuring device 146 by meansof which the actual values of the at least two parameters of the inletair stream 152 that is to be conditioned are determinable andtransmissible to the control device 160 by means of a control ormeasuring signal 172.

The control device 160 comprises a memory device 162 in which a model164 or a model-based correlation 164 between a plurality of possibleactual values of the at least two parameters of the inlet air stream 152and the operating states of the conditioning system 114 is stored.

For example, provision may be made for a parameter map 166 and/or acorrelation function 168 to be stored by means of the memory device 162.

On the basis of and/or by using the model 164, an operating state of theconditioning system 114 can be selected from the determined actualvalues of the at least two parameters of the inlet air stream 152 bymeans of the control device 160.

In order to set the conditioning system 114 into this operating state,one or more control signals 158 are transmitted to the conditioningdevices 122 of the conditioning system 114 by means of the controldevice 160.

Furthermore, the conditioning system 114 may comprise a regulatingdevice 170.

In particular, the regulating device 170 is connected to the controldevice 160 and also to a measuring device 146 for the purposes ofdetermining the actual values of the at least two parameters of theoutput air stream 154.

It can then be determined by means of the regulating device 170 as towhether the operating state of the conditioning system 114 selected bymeans of the control device 160 actually leads to the maintenance of thedesired target values of the at least two parameters of the output airstream 154.

Control or measuring signals 172 are exchanged between the measuringdevices 146, the control device 160 and the regulating device 170.

As can be perceived in particular from FIG. 4, the control signal 158that is being supplied to the conditioning devices 122 is an effectivecontrol signal 158 e which is composed of two control signals 158,namely, a control signal 158 s from the control device 160 and a controlsignal 158 r from the regulating device 170.

Preferably thereby, only a slight correction of the control signal 158 sfrom the control device 160 is effected by means of the regulatingdevice 170 since, preferably on the basis of the model 164, an operatingstate of the conditioning system 114 and in particular that of theconditioning devices 122 which ensures maintenance of the target valuesof the at least two parameters of the output air stream 154 has alreadybeen obtained by means of the control device 160. By monitoring thedeviation of the actual values of the at least two parameters of theoutput air stream 154 from the target values, functional monitoring ofthe conditioning system 114 can preferably be effected in order todetermine malfunctions and disturbances. The regulating device 170 maythus comprise a monitoring device 171.

The control signals 158, 158 e, 158 s, 158 r can, for example, berepresented as vectors and in particular as correcting-variable vectorsu=[u1 u2 u3]^(T). The entries for a correcting-variable vector arepreferably the correcting variables of the individual conditioningdevices 122.

In particular in the case where the contribution of the regulatingdevice 170 to the effective control signal 158 e is small and amounts toless than approximately 20% for example, and in particular less thanapproximately 10%, provision may be made for the regulating device 170to be operated using a linear regulation concept.

Based on the model 164, optimal control signals 158 for the coolingdevice 126, the heating device 124 and the humidification device 128 canbe produced by means of the control device 160.

Preferably, an expanded target value range 174 of the at least twoparameters, particularly the air temperature and the air humidity can beused.

For example, the target value range 174 is given by the connecting linebetween two working points 176 in a diagram wherein the air temperature(in ° C.) is plotted against the air humidity (in g water/kg dry air)(see FIG. 5).

The working points 176 are, in particular, a summer working point 176 sin which the conditioning system 114 is operable in an energy-efficientmanner especially in the summer, and a winter working point 176 w inwhich the conditioning system 114 is operable in an energy-efficientmanner especially in the winter.

The summer working point 176 s corresponds to an air temperature ofapproximately 30° C. and a relative humidity of approximately 65% forexample.

The winter working point 176 w corresponds to an air temperature ofapproximately 20° C. and a relative humidity of approximately 55% forexample.

In dependence on the actual values of the air humidity and the airtemperature of the inlet air stream 152, different operating states ofthe conditioning system 114 have to be realized in order to adhere tothe target values, i.e. for the purposes of achieving actual values ofthe parameters of the output air stream 154 that lie within the targetvalue range 174.

As can be seen on the basis of the point A in FIG. 5 for example, bothhumidification and heating of the inlet air stream 152 must be effectedin the case of very cold and dry air.

In the case of hot dry air (point B), humidification of the inlet airstream 152 may be sufficient for adherence to the target values.

In the case of humid air (point C), provision may be made for the inletair stream 152 to be cooled and thereby dehumidified, and subsequentlyfor it to be heated (heated-up).

As can be perceived from FIG. 6, there are effectively five differentregions, i.e. the regions I to V, which can be distinguished from oneanother in the air temperature-air humidity diagram.

If the actual values of the inlet air stream 152 result in a point inthe region I, then isoenthalpic humidification may be sufficient foradherence to the target values.

In region II, provision may be made for cooling and humidificationprocesses for adherence to the target values.

In region III, cooling together with resultant dehumidification as wellas heating of the inlet air stream 152 are preferably effected in orderto adhere to the target values.

In region IV, the inlet air stream 152 is preferably merely heated foradherence to the target values.

In region V, both humidification and heating of the inlet air stream 152is effected in order to adhere to the target values.

In particular, very rapid changes of the actual values of the at leasttwo parameters of the inlet air stream 152 can occur due to changes inthe weather.

For example, a change in status from region I to region IV can occur sothat the operating state of the conditioning system 114 has to bechanged from an isoenthalpic humidification process to a heatingprocess.

With increasing absolute humidity due to the onset of rain for example,a change in the weather from region I to region III can occur forexample. Consequently, there has to be a change-over from anisoenthalpic humidification process to a dehumidifying process, inparticular, by means of the dehumidifying device 130 and/or by means ofthe cooling device 126, and also heating by means of the heating device124.

Such a change-over or switch-over can be accomplished in a particularlysimple and reliable manner by means of the model 164.

In FIG. 8, there is illustrated the signal flow of the pilot controlprocess that is implementable by means of the control device 160.

As can be perceived from FIG. 8, the working points 176 s, 176 w as wellas the control or measuring signal 172 from the measuring device 146 aresupplied as input variables to the control device 160.

On the basis of the model 164, a check or measuring signal 172 which ispassed on to the regulating device 170 as well as the control signal 158s for controlling the conditioning devices 122 are produced by means ofthe control device 160.

The computation of the control signal 158 s from the control device 160(pilot signal) is preferably effected by the solution of an optimisationproblem.

For example, a linear energy function is used as the function that is tobe minimized and in particular a cost function and/or quality function:

E(u _(d1) ,u _(d2) ,u _(d3) ,a _(d1))=p ₁ u _(d1) +p ₂ u _(d2) +p ₃ u_(d3) +p _(d1) a _(d1)  (equation 1).

The variables u_(d1), u_(d2), and u_(d3) are correcting variablecomponents of the pilot control process by virtue of which the energyfunction E is preferably minimized. The quantity a_(d1) preferablyindicates the target value within the target value range 174 and inparticular within the spray booth air conditioning window (the so-calledDrying Line).

The target value is set at the winter working point 176 w for a_(d1)=0and at the summer working point 176 s for a_(d1)=100. The variables p₁,p₂, p₃ and p_(d1) are fixed weighting factors and indicate the linearcost factor of the individual conditioning devices 122.

Equation 1 is preferably minimized using the following auxiliaryconditions:

0≦u _(d1) ,u _(d2) ,u _(d3) ,a _(d1)≦100  (auxiliary condition 1)

and

v _(Winter) +a _(d1) v _(d1) =u _(d1) v _(cool) +u _(d2) v _(heat) +u_(d3) v _(humidifier)   (auxiliary condition 2).

Auxiliary condition 1 preferably ensures that the correcting variableskeep the preset boundaries i.e. remain within the preset target valuerange 174. Auxiliary condition 2 preferably ensures that the solution ofthe optimisation problem is on the energy-optimal point of theconnecting line between the summer working point 176 s and the winterworking point 176 w, i.e. on the Drying Line.

The vectors v _(cool), v _(heat), and v _(humidifier) are preferablydirection vectors in the enthalpy-humidity diagram. The length anddirection of the vectors preferably result from the momentary state ofthe inlet air stream 152 and the static model behaviour of theconditioning devices 122. The vectors are preferably determined from themodel equations of the conditioning system 122.

The direction vector v _(Winter) preferably describes the vector fromthe state (working point) of the inlet air stream 122 to the winterworking point 176 w. The vector v _(d1) preferably describes the vectorfrom the winter working point 176 w to the summer working point 176 sand lies on the Drying Line or runs along the Drying Line. An optimalvector v _(res) and hence a preferred operating state of theconditioning system 114 can thereby be determined by means of thecomputed factors a_(d1) (see FIG. 7).

The equation 1 and the auxiliary conditions 1 and 2 describe a linearoptimisation problem.

The optimisation problem can preferably be solved iteratively by asimplex algorithm in order to match the solution, in particular on-line,to the changing weather conditions. The static solution of the model andthus the optimisation problem preferably alter in the event of a changeof the environmental variables.

Optimal operation of the conditioning system 114 can thereby preferablybe always ensured by the model-based selection of the operating state.

1. A method for the conditioning of air, comprising: determining theactual values of at least two parameters of an inlet air stream of aconditioning system in which the air is to be conditioned; selecting anoperating state of the conditioning system on the basis of a model bymeans of which a plurality of possible actual values of the at least twoparameters is linked to operating states of the conditioning system;setting the conditioning system into the selected operating state sothat an output air stream of the conditioning system is produced inwhich the actual values of the at least two parameters lie within presettarget value ranges.
 2. The method in accordance with claim 1, whereinthe operating state of the conditioning system is selected on the basisof a parameter map, by means of which a plurality of possible actualvalues of the at least two parameters is linked with the operatingstates of the conditioning system.
 3. The method in accordance withclaim 1, wherein the operating state of the conditioning system isselected on the basis of a correlation function by means of which aplurality of possible actual values of the at least two parameters islinked with the operating states of the conditioning system.
 4. Themethod in accordance with claim 1, wherein one parameter is the airtemperature and a further parameter is the air humidity.
 5. The methodin accordance with claim 1, wherein a plurality of possible actual valuecombinations of the at least two parameters is linked with a respectiveoperating state of the conditioning system by means of the model.
 6. Themethod in accordance with claim 1, wherein the selectable operatingstates of the conditioning system are pre-defined operating states ofthe conditioning system which each comprise a pre-defined operatingstate of a humidification device, a pre-defined operating state of adehumidifying device, a pre-defined operating state of a heating deviceand/or a pre-defined operating state of a cooling device.
 7. The methodin accordance with claim 1, wherein, after being set into the selectedoperating state, the conditioning system is set into a readjustingoperating state in which a deviation of the actual values of the atleast two parameters of the output air stream from the preset targetvalues is determined and in which, for the purposes of furtherapproximation to or equalization of the actual values with the targetvalues, readjustment of the conditioning system is effected.
 8. Themethod in accordance with claim 1, wherein a determination is made bymeans of a monitoring device as to whether a deviation of the actualvalues of the at least two parameters of the output air stream from thepreset target values exceeds a preset maximum deviation.
 9. The methodfor supplying air to a work-piece processing system comprising a methodin accordance with claim 1, wherein the output air stream of theconditioning system is supplied as a processing air stream to aprocessing area of the work-piece processing system and in that theplurality of possible actual values of the at least two parameters ofthe inlet air stream of the conditioning system is linked with theoperating states of the conditioning system by means of the model insuch a manner that the derivable actual values of the at least twoparameters of the processing air stream lie within preset target valueranges.
 10. A conditioning system for the conditioning of air comprisinga control device and a measuring device for determining the actualvalues of at least two parameters of an inlet air stream of theconditioning system in which the air is to be conditioned, wherein anoperating state of the conditioning system is selectable by means of thecontrol device on the basis of a model by means of which a plurality ofpossible actual values of the at least two parameters is linked withoperating states of the conditioning system, and wherein theconditioning system is settable into the selected operating state bymeans of the control device so that an output air stream of theconditioning system is producible in which the actual values of the atleast two parameters lie within preset target value ranges.
 11. Theconditioning system in accordance with claim 10, wherein the controldevice comprises a memory device in which a parameter map and/or acorrelation function is stored whereby a plurality of possible actualvalues of the at least two parameters is linked with the operatingstates of the conditioning system by means of the parameter map and/orby means of the correlation function.
 12. The conditioning system inaccordance with claim 10, wherein the conditioning system comprises ahumidification device, a dehumidifying device, a heating device and/or acooling device.
 13. The conditioning system in accordance with claim 10,wherein the conditioning system comprises a regulating device by meansof which the conditioning system is settable into a readjustingoperating state in which a deviation of the actual values of the atleast two parameters of the output air stream from the preset targetvalues is determinable and in which readjustment of the conditioningsystem for the purposes of closer approximation to or equalization ofthe actual values with the preset target values is implementable. 14.The conditioning system in accordance with claim 10, wherein theconditioning system comprises a monitoring device by means of which itis determinable as to whether a deviation of the actual values of the atleast two parameters of the output air stream from the preset targetvalues exceeds a preset maximum deviation.
 15. A work-piece processingsystem comprising a conditioning system in accordance with claim 10,wherein the output air stream of the conditioning system is feedable toa processing area of the work-piece processing system as a processingair stream and in that the plurality of possible actual values of the atleast two parameters of the inlet air stream of the conditioning systemis linked with the operating states of the conditioning system by meansof the model in such a manner that the derivable actual values of the atleast two parameters of the processing air stream lie within presettarget value ranges.